Though the vast, vast majority of analog watches tell time on a 12-hour scale, there are several watchmakers that have historically produced watches displaying all 24 hours of the day. Why? Well, for the most part, 24-hour analog watches are preferred by pilots, medical professionals, astronauts and other professionals who operate on a 24-hour time system (a.k.a. army time), not to mention explorers and adventurers traveling to areas and regions where there isn’t a clearly divided nighttime and daytime (it’s one of the reasons the Rolex Explorer II has a GMT hand). For the most part, 24-hour watches remain horological oddities, and while some manufacturers still make 24-hour analog watches, it’s the vintage stuff that proves to be the most interesting.
Raketa Antarctic Submariner

What we like: Russian watch brands like Raketa are the most notable producers of 24-hour watches, mostly due to the sheer amount of them made. The Raketa Antarctic Submariner here is just one of the many, many iterations of 24-hour watches produced by Raketa, built with polar explorers in mind, all of whom would experience 24-hour daylight during the summer.
From the seller: Brand new with passport (new old stock). Passed full service by professional watchmaker. Works very well. All mechanisms are fully functional and keeps correct time.
Zodiac Hermetic Aerospace Jet

What we like: The Hermetic was launched in 1962 (the “Aerospace Jet” moniker would come years later), and aside from featuring a 24-hour dial configuration and movement, the Hermetic was notable for its use of the water-proofing system its stabelmate, the Sea Wolf. Thus, despite its lithe case shape, this otherwise classy timepiece was indeed meant to be used as a tool.
From the seller: [Case is in] great condition, no serious nicks or scratches. [Dial has] no blemishes.